Island



(No Model.) 2 SheetsSheet 1.

. L. L. BURDON.

M'ANNER 0P PRODUCING SEAMLESS OOMPOUNDWIRE.

No. 446,619. Patented Peb.'17,189 1" 'WITNEEEESL INVENTEIRH f ll (NoModel.) 2 Sheets-Sheet 2.

L. L. BURDON; MANNER 01-" PRODUCING SEAMLESS COMPOUND WIRE.

No. 446,619. Patented Feb. -17,'189l.

WITNESSES. lNvEN-rmR.

.a'rnivr tui ion,

LEVI L. BURDON, OE PROVIDENCE, .RIIODE ISLAND, ASSIGNOR TO THE BUR-DONSEAMLESS FILLED VIBE COMPANY, OF SAME PLACE.

M'ANNER OF PRODUCING SEAIVILESS COMPOUND WIRE.

SPECIFICATION forming part of Letters Patent No. 446,619, dated February17, 1891. Application filed July 29, 1890, Serial No. 360,273. (Nomodel.)

To ctZZ whom it may concern.-

Be it known that I, LEVI L. BURDON, acitizen of the United States,residing at Providence, in the county of Providence and State of RhodeIsland, have invented certain new and useful Improvements in the Mannerof Producing Seamless Compound \Vire; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and to letters of reference marked thereon, which form a part of thisspecification.

My present invention has relation to improvements in the manufacture ofseamless compoundingots and wire produced therefrom. Said invention,however, appertains more particularly to seamless wire in whicha core ofbase metal or other metal having a rela tively less value than the outershell or plate is united to a comparatively thin seamless shell of goldor other suitable metal, such wire being especially adapted for themanufacture of watcl1ehains, finger-rings, bracelets, pins, the.

In the operations employed in the reduction to wire of seamless compoundingots it is very desirable that the metal be uniformly acted upon inorder to preserve its integrity throughout, especially at the union ofthe core and outer shell, because otherwise the percentage of waste isso excessive as to preclude the employment by jewelers of suchimperfectly united seamless wire in lieu of the common seamed platedwire.

Various attempts have been and are still being made to reduce seamlesscompound ingots to a piece of continuous wire having a uniform size andquality throughout; but such former attempts, so far as I am aware, havebeen attended with failure or indifferent results, the product beingirregular in size and not su'lficiently uniform in quality. IIeretoforethe practice has been to attenuate or reduce plated ingots, particularlysuch as are cylindrical in form, to a size adapted to be passed througha draw-plate by means of powerful squeezing-rolls provided with a seriesof \I-shaped circumferential grooves {I I i i a gradually decreasing insize, between which grooves the ingot or rod is successively passed.Sometimes the grooves are semicircular in cross-section, although stillother forms of grooves have been used; but in all of them the action isto compress the metal most at two or more parts throughout the length ofthe ingot, while at the same time the metal not in actual contact withthe dies or grooves is distended or squeezed out laterally, therebytending to separate the atoms or fibers in that direction. Moreover,such method of reduction produces an unequal strain or tension upon thetwo metals composing the ingot, and frequently results in disunitingthem in spots, which latter, after a few passes, develop into placeshaving somewhat the appearance of abrasions, such portions when drawninto wire being cutout as waste stock and possessing no commercialvalue. In such former methods of reduction the ingot or rod is turnedslightly, so as to present a new surface to the rolls at each pass. Ihave found it to be practically impossible to thus produce wirepossessing the necessary homogeneity essential to plated wire adapted tothe use of jewelers. Sometimes power-hammers or trip-hammers have beenused to reduce plated ingots; but the result is substantially the sameas though they had been passed between driven rolls, as before stated.

It should be borne in mind that the metal is worked cold, although it isfrequently annealed during the reducing operation. I am aware that whena bar of iron or other metal is thus acted upon, although it is usuallyworked hot, the result is practically satisfactory; but when a compoundingot is substituted and worked cold the result is quite dif ferent, forreasons before given.

I have discovered by extensive experimenting that in order to reduce acompound ingot into wire which is well adapted for jewelers purposes awhat may be termed swag-ing process produces the best results. Usuallyin working metals cold the effect seems to to harden it, whereas by theswaging proces about to be described it ap'pearsto soften the metal,because after a considerable amount of swaging the pieces of metal canthen be bent more readily than metal reduced to the IOO - the rate ofspeed being several hundred comp by this improved method not onlyreduces the metal by squeezing it toward the center same extent by othermethods. The swaging mechanism which I have employed in reducingcompound ingots requires a series of dies in halves, the die-cavitiesthereof gradually decreasing in size. The dies are mounted in the end ofa strong hollow shaft adapted to revolve rapidly. he dies are fitted tomove slightlyin a lateral direction, each half being backed by a steelblock or dog. Arranged around the head of the machine are a number ofnormally stationary cams or swageblocks susceptible of adjustment, eachhaving a spring which serves to maintain the cams in position except forthe instant when they are in contact with the dogs. New upon introducingthe end of the ingot between the revolving dies the traveling dogssuccessively engage the free ends of the cams, thereby at eachengagement slightly reducing the metal by compression and elongation,the ingot meanwhile not being revolved. After the ingot has been actedupon byone pair of dies the latter are removed and the next smaller pairsubstituted and the ingot again acted upon, the operation being repeateduntil the desired reduction is attained or until the size of the rodrenders it susceptible of being passed through a draw-plate. Bythisemeth- 0d of reduction or swaging all parts or pertions of the metalacted upon are subjected at the same time to the same or a uniformdegree of pressure, thereby producing a practically perfect homogeneityof the metal. It will be observed that the action of the mechanism is tosqueeze the dies together upon the metal from opposite sides at eachsuccessive engagement of the dogs and cams,

pressions per minute. By reason of such compressive action there existsno counter tendency to stretch or tear the metal at some other part atthe same time, as is common to the usual hammering,rolling, and drawingprocesses. Moreover, when rolls and hammers are employed, they furtherserve to harden the surface of the metal, thereby forming a skin, whichrenders the rod or ingot very stilt, which is especially undesirable incompound ingots. \Vith the aid of compressing mechanism no such skin isformed, the compression being a squeeze and not a blow, and as the diesarenearly cylindrical it follows that nearly all the atoms" or particlesof the metal are simultaneously acted upon from circumference to centerat a uniform pressure. 1 wouldstate, further, that each individualsqueeze does so little of the aggregate work of reduction that there isno violent action upon the metal such as accompanies other cold-workingmethods. Swaging from all directions while in contact with the dies, butit also serves to hold the ingot centrally until it has received theextreme degree of pressure from the dies. Still another advantagederived 'from the cold-swaging process is that as it acts to condense orcompress the entire mass equally there are no lire cracks or seamsdeveloped in the metal during the several annealings. When, however, themetal is worked cold, as in rolling, hammering, or drawing, tire-cracksfrequently occur in annealing the metal. In some cases the percentage ofwaste is so great from this cause alone as to preclude the manufactureof certain grades of compound ingots.

The object I have in view is to overcome the hereinbefore-describeddefects or disadvantages inherent in the former methods of producingseamless compound wire. To that end niyinvention consists,essentially,in the following-named steps, viz: first, forming a core orcenter portion of suitable metal and a seamless exterior shell or tubeof metal havin g a greater relative value than the core portion; next,suitably preparing the contiguous surfaces of the core and outer shelland uniting them together, thereby producing the ingot; then repeatedlysubjecting the ingot to a squeezing or swaging operation, which acts togradually and uniformly reduce it from circumference to center, and atthe same time elongating it, and, finally, subjecting the thus reducedingot to drawing mechanism, which still further elongates it to seamlesswire having the desired form and size cross-section ally, all as will bemore fully hereinafter set forth and claimed.

In the appended two sheets of drawings, illustrating my invention,Figure 1 shows a side elevation of'the center or base metal coreportion. Fig. 2 is a longitudinal sectional view of the outer seamlessshell of metal having a relatively greater value than the core. Fig. 3shows a thin piece of solder adapted to be wrapped around the core. Fig.at shows the ingot in partial section before being soldered. Fig. 5shows the same in reduced scale, mounted in afurnace and being subjectedto a flame to fuse the solder. Fig. b is a side elevation of a swagingor squeezing machine adapted to uniformly reduce the ingot fromcircumference to center, thereby at the same time elongating it. Fig. 7is an enlarged transverse sectional View taken through the head portionof the machine, showing an end of the seamless ingot introduced betweenthe dies and in the act of being slightly reduced and correspondinglyelongated. Fig. 8 is an end view of the front head of the machine. Fig.9 is the same with the front plate or cover removed, the dies beingrepresented at the instant of their engagement with the reduced ingot orwire. Fig. 10 is a similar view of the parts, the revolving dies,however, being disconnected from the dogs at the instant, as insuccessively passing from one cam to another. Fig. 11 is a plan view ofthe machine, the head portion being in horizontal section. Fig. 12represents in plan view a portion of a drawing-machine-that is, amachine provided with a draw-plate in which is formed a series of holesgradually diminishing in size, through which the wire is successivelypassed; and Fig. 13 is a front view of the draw-plate itself.

A manner of constructing the seamless ingot preparatory to being reducedto com pound seamless wire is as follows: The core portion a of theingot is usually composed of brass or base metal. The core may have anypractical form and size-as, for example, it may be cylindrical ortapering and round or polygonal cross-scctionally. The outer shell I) ofthe ingot consists of a seamless tube of fine metal or suitably-alloyedmetal, its form transversely being substantially like that of the coreportion to which it is to be united. Sometimes the shell 1) itself iscomposed of plated or compound stock, thereby making it of less relativevalue than the tube first referred to. There are several ways of unitingthe core and shell, one manner of attaching them being to snugly fit thecore into the shell, leaving a space or chamber at the top, in whichloose solder is placed, which latter melts and runs down around andbetween the contiguous surfaces upon being subjected to a propertemperature. Another way is to make the core a little smaller indiameter than the bore of the tube and introduce between the adjacentsurfaces a layer or sheet 0 of thin solder, (see Figs. 3 and l,) whichfuses upon the proper application of a suitable degree of heat. Stillother ways of uniting the parts are to first cover or coat the core withsolder, or the inner surface or bore of the outer shell itself may belined with solder, the core being next introduced and the wholesubjected to heat, as before stated. Again, the two parts a and b may befitted together and then united by sweatingthat is, a union of one ormore of the low-fusing metals with which the core and shell are alloyed.It is obvious that the surfaces of the metal in any case must first besuitably prepared or treated, as with borax,

in order to facilitate the union of the parts. The ingotA may beattached by an end a to a revolving gear-driven spindle a the Wholebeing inclosed within a hood or furnace f, provided with an aperturethrough which the flame of a burner d is directed onto the revolvingingot, as in Fig. 5.

After the outer shell is properly attached to the core, substantially asbefore stated, the ingot is removed from the furnace and its endintroduced cold between a pair of dies I), Figs. (5 to 11, mounted inthe front end of the hollow shaft H of a swaging-maohine B, which actsto slightly squeeze and reduce the metal of the ingot from circumferenceto center by reason of the rapid successive engagement of theoppositely-arranged pivotallymounted dogs cl with the series of normallystationary adj ustably-mounted spring-resisted cams or swage-blocks 'u.The contig- Vuous surfaces of the dogs and cams are preferably so curvedthat they will roll into each metal.

other, the rolling action being similar to the cpieyeloidal curvefrequently used in gear ing. As the dogs pass each cam a straight springs in each, Fig. '7, vibrates themrearwardly to the normal positionagainst their respective steps '11", (See Figs. 9 and 10.) The cams arebacked by adj Listing-blocks 72, into which the cams are fitted to swingor vibrate somewhat. Said blocks are adjusted by means of strong boltsm, passing radially through the head it of the machine. The dies areprevented from moving endwise by a follower h, screwed into a flange h,secured to the front end of the hollow shaft or spindle H.

In reducing the compound ingot A to scamless wire u adapted to be passedthrough the holes of a draw-plate 7., the ingot is first repeatedlypassed through the swaging-machine,the dies D thereof being changed eachtime for others, the several die-cavities s gradually decreasing in sizeuntil the desired reduction is attained. The ingot or rod which issuitably annealed is held and prevented from turning by the attendantduring each pass through the dies, the result being an attenuated rodpractically true and homogeneous throughout its length, no seams,blisters, or abrasions being apparent. The action of the dies, ashereinbefore stated, is to gradually squeeze the metal or atomscomposing it 9 from circumference to center as contradistingnished fromingots reduced by the action of blows, as in hammering, which latter notonly hardens and crystallizes the metal, but also acts to distort itfrom a true shape, the latter being particularly true when the reductionis effected by rolling processes.

After the swaging-machine has reduced the ingot to a rod or Wire tohaving the desired size it is then subjected to a drawing process-- 1o 5that is, an end of the rod is inserted through a hole 70 0f a draw-plateis, mounted in a drawing-machine, Figs. 12 and 13. Machines of this typeare well known. The jaws 1, attached to the driving-chain o seize theend of the rod and pull it through the draw-plate, thereby slightlyreducing the rod transversely, but at the same time elongating it. Therepeated passage of the wire through the gradually-diminishing holes kof a suitable draw-plate finally reduces it to the desired form and sizecross-sectionally, the productbeing compound Wire composed of a seamlessexterior surface of gold or other fine metal of uniform thickness unitedto an inner portion of; low-grade I20 I would state that it is obviousthe ingot and wire should be properly annealed at intervals during theprocess of reduction.

I make no specific claim herewith to the manner of producing seamlesscompound in- 12 5 gots adapted to be reduced to seamless wire, as ingotsof this class have been previously patented-as, for example, see UnitedStates Patents Nos. 29l,722, 327,655, 381,527, 391,736, 419,598,422,713, and 432,690. Neither do I I30 inbefore described, in thereduction by cold working of compound ingots to rods or wire,

vthe same consisting in repeatedly subjecting the suitably-preparedingot to a squeezing or swaging operation, which acts to graduallyreduce it from circumference to center, and at the same time attenuatingthe ingot until the desired size is attained.

2. The improvement, substantially as hereinbefore described, in thereduction by coldworking of compound ingots to rods or wire, the sameconsisting in repeatedly subjecting the prepared ingot to a squeezing orswaging operation, which acts to gradually and uniformly reduce it fromcircumference to center and at the same time elongating it, and nextsuccessively passing the prepared rod thus reduced through drawingmechanism which still further elongates it and gives to the wire thedesired form and size cross-sectionally.

The improvement hereinbefore described in the manufacture of seamlesscompound wire, the same consisting in first producing a seamlessexterior shell of alloyed fine metal, or even a seamless compound tube;next introducing a suitable metallic core into said shell, then unitingthe core and shell, thereby forming the ingot; next repeatedlysubjecting the suitably-prepared ingot to a squeezing or swagingoperation, which acts to gradually and uniformly reduce it fromcircumference to center and at the same time elongating it, and finallysubjecting the reduced ingot to drawing mechanism, which acts to stillfurther elongate it and gives to the seamless wire thus produced thedesired form and size cross-sectionally.

In testimony whereof I have affixed my sig- 5

